Retaining device



Jan. 26, 1960 P. HELLER RETAINING DEVICE Filed Aug. 31, 1955 INVENTOR Poul Hell'er. FM ,ATTORNEY United States Patent 2,922,901; RETAINING DEVICE Paul Heller, Richmond Hill, N.Y., assignor to Westinghouse Electric Corporation, East Pittsburgh, Pa., a corporation of Pennsylvania 1 Application August 31, 1955, Serial No. 531,720 1 Claim. (Cl. 313-76) 'The present invention relates to means for retaining beam controlling apparatus of cathode ray tubes. More particularly, the invention relates to means for retaining a deflection yoke of a cathode ray tube at a predetermined location along the neck of such a tube.

In a cathode ray tube, either of the instrument type or the type used for television purposes, means must be provided for deflecting the electron beam to control the image produced by the tube. The most customary method of controlling the electron beam is to provide means, usually of electromagnetic type, for deflecting that beam horizontally and vertically according to signals received by or produced in the apparatus with which the tube is employed.

In by far the greatest number of cases the deflection of the electron beam in a cathode ray tube is accomplished by means of a deflection yoke which may be comprised of two pair of coils positioned at an appropriate point along the neck of the tube, one pair of coils controlling vertical deflection of .the electron beam and the other pair of coils controlling horizontal deflection thereof.

It has also been found very desirable to provide some means for centering or adjusting the undefiected position of the electron beam relative to the screen of the cathode ray tube in order that the images may be reproduced correctly centered on the screen area. One arrangement suitable for accomplishing beam centering is comprised of two annular permanent magnets. The two magnets are disposed side-by-side surrounding the neck of the cathode ray tube and are mounted for independent rotation about said neck.

The deflection yoke is customarily adapted to be placed around the neck of a cathode ray tube and to be slid along that neck to an appropriate position, usually right up against the flaring portion of the tube. The deflection yoke must be fixedly retained or positioned around the neck of the cathode ray tube so that the image produced by the tube will appear in correct position for viewing.

One prior arrangement for retaining the deflection yoke on the neck of the cathode ray tube consists of securing the deflection yoke to a support or bracket which is in turn secured to the cabinet or chassis associated with the tube.

The present invention is concerned with a means for retaining the deflecting yoke at a predetermined location along the neck of a cathode ray tube, the deflection yoke being supported'on the neck of the tube independent of any support of the above-mentioned type.

An object of this invention is to provide an improved retaining means for beam controlling apparatus of cathode ray tubes.

It is another object of this invention to provide a retaining means for a deflection yoke of a cathode ray tube which will hold the yoke in a proper fixed position.

It is another object of the invention to provide a retaining means for a deflection yoke of a cathode ray tube which will retain the deflection yoke at a predetermined location along the neck of the tube.

. It is another object of the invention to provide a retaining meansfor the deflection yoke of cathode ray tubes utilized in television receivers which is less costly than those presently in use.

It is another object of the invention to provide a retaining means for a deflection yoke of a cathode ray tube which in addition provides a novel means for mounting a beam centering arrangement of the above-mentioned type.

These and other objects are effected by my invention as will be apparent from the following description taken in accordance with the accompanying drawing throughout which like reference characters indicate like parts, and in which:

Figure 1 is a side elevational view of the present invention a cathode ray tube; V Fig. 2 is a side sectional view of the retaining device; Fig.3 is a side elevational view of Fig. 2; and

Fig. 4 is a view similar to Fig. 3 illustrating a manner in which. elements for centering the electron beam of a cathode ray tube may be mounted on the retaining device.

Referring to the drawing, and for the present more particularly to Figs. 1, 2 and 3 thereof, a cathode ray tube shown in outline form is indicated by the numeral 10 and is comprised of a neck portion 12 and a flare or bulb portion 14. The cathode ray beam of the tube 10 is deflected by means of a deflecting coil unit or yoke indicated by reference numeral 16. The yoke is placed around the neck portion 12 of the tube 10 and is slid along that neck portion to an appropriate position, usually right up against the flare portion 14 of the tube 10 (Fig. 1).

The retaining device indicated by the reference numeral 18 comprises a base portion 20 and integral flange portions 22 and 24. The base portion .20 has a central aperture through which the neck portion 12 of the cathode ray tube 10 is adapted to pass. The flange portion 22 is provided with a plurality of slots 26 (Figs. 3 and 4) which are utilized to key the retaining device 18 to the deflection yoke 16 to insure that there will exist no relative movement between the two. The flange portion 24 is segmented and a plurality of segments 28 extend longitudinally and outwardly from the base portion 20. The segments 28 are made of a flexible material and are made to taper inwardly towards their free ends (Figs. 2 and 3). The segments 28 are laterally spaced from each other a distance less than the diameter of the neck 12 so that when the retaining device 'neck of the cathode ray tube the segments 28 will closely engage the neck 12. The retaining device 18 will substantially prevent the yoke 16 from rotating about the neck 12 and it will also retain the yoke 16 at the appropriate location along the neck of the tube. It is most of a retaining device mounted on the neck section of 18 is placed on theyoke 16 is properly positioned on the neck I outer surfaces will be parallel (Fig. 1) to the longitudinal axis of the cathode ray tube and there will be a minimum tendency for the clamping ring 32 to slip oil the segments.

In he ill ra ed, embo im t of hi invent on t r ain ng. d e .1 s s w s a rea r ba k cover for the deflection yoke 16. Thedevice 18 ispreferably made of some heat resistantmaterialsuchasvheat resistant cellulose acetate,so'that it will notdistort excessively due to prolonged contact .of .thesegments 28 with the neck 12 of the cathode ray tub e-10. The de-v vice 18 is also preferably made with the segments 28 molded because of the facility with which the plasticn la terial described may be shaped by that method, Thebase portion 20 of the device 18 ismolded witha plurality of circular ridges 35 which add structural strength to the base portion. It will beunderstood-that any otherrnode of shaping which seems appropriate may also be employed. I 1 g Y a It will be understood that a clamping ring other than the type shown in Fig. 1, such as a spring wire type hose clamp which employs only spring pressure may be-used.

I r This latter type would have the advantage of quick assembly as wellas having the property that itpwill automatically take up any cold flow that the'plastic may exhibit after a period of time. a a

Referring to Fig. 4 in detail, an electron beam centering arrangement is comprised of two annular permanent magnets 36 and 38. These magnets are mounted adjacent to the base portion 20 so as to be independently rotatable about the axis of the neck 12. of the cathode-ray tube It). An annulus of non-magnetic anti-rotational sheet material (not shown) may be positioned between the two magnets 36 and 38. The magnets 36 and 38' are provided with ears 36A and 38A which extend beyond the external periphery of the non-magnetic sheet material and facilitate turning of the magnets.

The retaining device 18 is molded so that the flange portion 24 is comprised of four segments 28. There is a tab 40 located between two of the segments ZS'and another tab 42 located between the other two segments 28. When the retaining device 18 is issued from the mold, the tabs 40 and 42 are parallel to the segments 28 (Fig.

42 a e hys ca rolled o e (m o n e t by mean of a heated tool) so that they firmly hold the magnets against the base portion or back cover 20 of the deflection yoke 16 (Fig. 4).

It will be understood that the tabs 40 andt42 which are integral with the retaining device 18 may be eliminated and small springs may be'used to hold the beam centering magnets; in addition, tabs or springs may be utilized between each of the segments 28. v 4

lthough the invention hasbeendescribed with'reference to certain specific embodiments it'will' be obviousto those skilled in the art that it is not so limited but is susceptible to-various changes and modifications without departing from the spirit thereof. Thus, by way of example, the retaining device need not be physically connected to the beam controlling apparatus if such apparatus is positioned'against the flaring portion of the cathode ray tube. Also, the retaining device may comprise a back ,or rear cover for an electromagnetic focusing device or other beam controlling apparatus which may be located on the neck of the cathode ray tube.

I claim as my-invention:

Electron beam centering apparatus tor cathode ray:

' tubes comprising, a supporting member including a radial- 3); After the two centering magnets and the anti-rota- I tional disc are slipped over the segments 28 and positioned adjacent to the'base portion 20, the tabs 40 and ly-extending baseportion having an aperturefor encompassing the neclc of the cathode, ray tube and a flange portion extendinglongitudinally from one side of said base portion for securing said member on the neck of the 7 tube, at least two annular permanent magnets positioned coaxially andisurrounding said flange portion, a thin nonmagnetic spacer between said magnets, and spring means mounted on one of said portions so as to extend outwardly beyond the surface of said flangeportion and rotatablyhold ,sa-id magnets on said supporting member.

References Cited in the file of this patent UNITED STATES PATENTS 2,234,720 De Tar Mar. 11, 1941 2,500,623 Babbs Mar. 14, 1950 2,513,929 Gethmann July 4, 1950 2,575,067 Mucher -Nov. 13, 1951 2,597,298 Court May 20, 1952 2,646,522 7 Shaw et .al. July 21, 1953 2 3, 2

Bowman Sept. 22, 1956 

